Ynot Posted September 21, 2006 Share Posted September 21, 2006 By 'Old analogue dimmers' are we talking about a variable auto transformer...Or even salt water dimmers :blink: :D :DSorry, guys, but I don't feel this is a valid "Myth". Dimmers are dimmers - each in it's time broke new ground and improved on certain areas.I thought the idea of the thread was ACTUAL myths.....Debating whether current kit is better than older stuff is, quite honestly, (like my pencil here), pretty pointless.. Link to comment Share on other sites More sharing options...
David A Posted September 22, 2006 Author Share Posted September 22, 2006 The responses to this thread do prove that it is a copmmonly held view that DMX is better than analogue, now DMX is not a dimmer system it is only a way of transferring information so there are garbage DMX dimmers and excellent analogue ones.There is a local theatre with 160 ch JTM which has minimal problems, while I have some clients who are on their 3rd generation of DMX dimmers.The commonly held view that ianything with digital in the title must be better than analogue is invalid when talking about dimmers especially in low use situations like schools and churches.If I was spending my money on a rig I would rather have 24 channels of JTM than 12 channel of generic DMX, and in 10 years time I know which will still be working. Link to comment Share on other sites More sharing options...
Wilf dLampy Posted September 22, 2006 Share Posted September 22, 2006 Taking the whole system, rather than just the dimmer, one advantage of most analogue lighting systems over most digital ones is that they respond quicker to the operator. If you are using a digital desk (particularly a complicated one) it's basically a computer which translates your input into electrical signals (this takes time). The electrical signals travel down the cable and then must be decoded at the other end by the dimmer (taking more time). A simple analogue setup doesn't have any of this encode/decode delay so the lights respond to the control faster. Older, poorer quality electronics makes this delay quite noticable. Now, this doesn't make analogue "better" than "digital", digital has it's advantages too. Link to comment Share on other sites More sharing options...
Ynot Posted September 22, 2006 Share Posted September 22, 2006 The responses to this thread do prove that it is a copmmonly held view that DMX is better than analogue, But that is PRECISELY the point! What is being discussed is NOT a 'myth', but a basic discussion about the relative merits of a whole HORDE of different types of dimming system, and to be honest, it's not going to come to any sort of conclusion any time soon! What's good in one situation may be totally untenable in others but absolutely brilliant in a third! It's all viewed from the user's perspective. ...now DMX is not a dimmer system it is only a way of transferring information so there are garbage DMX dimmers and excellent analogue ones. True. But that can be said of a multitude of kit, and again doesn't mean there's anything mythical going on. Let's not ignore the fact that this portion of the thread was started by (and seriously - no disrespect intended) a 14 yr old lad with aspirations. Let's leave this one, shall we?? Link to comment Share on other sites More sharing options...
Bean Posted September 22, 2006 Share Posted September 22, 2006 Just like to point out now that the idea wasn't mine...(Sorry dad) Link to comment Share on other sites More sharing options...
Brian Posted September 22, 2006 Share Posted September 22, 2006 To clear up a couple of previous myths... MYTH 1 - PAR64 Lamps are Inefficient in Long Nose Cans The hole diameter in a PAR64 colour frame is 200mm. The lamp in a PAR64 can is 300mm back from the colour frame. A quick Tangent gives us an angle of 41 degrees. A CP62 MFL lamp has a 50% beam angle of 25 x 14 degrees and a 10% beam angle of 39 x 24 degrees. So, the 10% beam fits within the output angle of the can. An EXG WFL lamp has a 50% beam angle of 57 x 21 degrees and a 10% beam angle of 73 x 36 degrees. MYTH BUSTED for MFL If I get bored I'll work out how much light is lost from an EXG. MYTH 2 - Wide Angle MR16 Lamps are Inefficient in Birdies The hole diameter in a PAR16 colour frame is 50mm. The lamp in a PAR16 can is 90mm back from the colour frame. A quick Tangent gives us an angle of 34 degrees. An EXN MR16 50w lamp has a 10% beam angle of 36 degrees So, the 10% beam fits within a gnats of the output angle of the can. MYTH BUSTED [EDIT] MYTH 3 - Coiled Extension Leads get Hot due to some wierd inductance/magnetic thing Practical experiment... Take one cassette type 10m extension lead rated at 10A uncoiled, 5A coiled. Put a 5A load on the end. Measure the mains voltage at each end of the lead. In the uncoiled state the input voltage was 237.5v and the output was 234.4v. Voltage drop 3.1v. In the coiled state the input voltage was 237.5v and the output was 234.4v. Voltage drop 3.1v. If coiling the cable made it act as an inductor then the inductor would have an impedance which means the voltage to the load would drop in the coiled state. It didn't. The voltage drop across, and hence the power dissipation in, the cable was constant. MYTH BUSTED If I get time I'll try it over the weekend with singles. Link to comment Share on other sites More sharing options...
jexjexjex Posted September 22, 2006 Share Posted September 22, 2006 Hi All. Just started paying attention to this thread and I'd like to throw a (possible) spanner into the parcan v beam angle issue. Someone earlier in the thread mentioned that the nose of the can absorbs some of the light. Maybe I'm being really thick here, but surely that would only be the case if the can was black. What if it was polished? Or would that not make much difference? Either way, I'm happy to bow to Brian's "myth busting" superior knowledge on this one. Still, onwards and sideways, another one... Myth of the day: You can never have too much blue on your stage... ...or so I was taught by the late Bob, who got me started in this lighting lark many years ago. Bob was definitely of the "old school" in his lighting ideas and ideals, but he used to trot that one out regularly. Anyone got any thoughts? Suppose it depends partly on your choice of shade of blue and what you're actually trying to achieve. Let's face it, you only have to mention "congo" on the usenet r.a.t.s newsgroup to start a war. Maybe it was just a premptive strike against the pink gel that is, apparently now taking over the world... :** laughs out loud **: Link to comment Share on other sites More sharing options...
Ynot Posted September 22, 2006 Share Posted September 22, 2006 you only have to mention "congo" on the usenet r.a.t.s newsgroup to start a war.Ah, but it's a very much one-sided war!:huh:After all, with FW on one side and the rest of the world on t'other it's hardly a fair fight, is it...?!! :** laughs out loud **: Link to comment Share on other sites More sharing options...
gareth Posted September 22, 2006 Share Posted September 22, 2006 But it's always good fun to see just how far we can wind him up! Link to comment Share on other sites More sharing options...
Ynot Posted September 22, 2006 Share Posted September 22, 2006 But it's always good fun to see just how far we can wind him up!Oh yes!! Link to comment Share on other sites More sharing options...
Jamtastic3 Posted September 23, 2006 Share Posted September 23, 2006 I have a myth, that I've never really understood. That you shouldn't use microphone (non DMX cable) cable when daisy chaining movers/intelligents. Now I've come across different venues who have intelligents using 3pin XLR cable to daisy chain and they never have any problems with the DMX signal. Also, I myself have used XLR (when there's no money) for movers and have never had any signal problems. Of course I'd always like to use the peoper cabling for any situation. SO what's the story here then??? Link to comment Share on other sites More sharing options...
dbuckley Posted September 23, 2006 Share Posted September 23, 2006 The story is well documented ewlsewhere in the blue room, please, lets not do it again here. Link to comment Share on other sites More sharing options...
Ynot Posted September 23, 2006 Share Posted September 23, 2006 I have a myth, that I've never really understood.That you shouldn't use microphone (non DMX cable) cable when daisy chaining movers/intelligents.Definitely NOT a myth, but a FACT.Go use SEARCH and you'll find out clearly why! Link to comment Share on other sites More sharing options...
mark_s Posted September 23, 2006 Share Posted September 23, 2006 ...you shouldn't use microphone (non DMX cable) cable when daisy chaining movers/intelligents. Not only is that a myth as others have pointed out, it applies for any DMX runs, not just when daisy-chaining fixtures. Link to comment Share on other sites More sharing options...
johnhuson Posted September 24, 2006 Share Posted September 24, 2006 I have a myth, that I've never really understood. That you shouldn't use microphone (non DMX cable) cable when daisy chaining movers/intelligents. Not Myth it's Fact....read the DMX512 specification. Before we get back onto the Mic/DMX cable debate, you should read this thread. as well as many others on this site that touch on the subject. Yes mic cable may work most of the time but it'll trip you up one day and the cost of cable isn't that different so why bother! Link to comment Share on other sites More sharing options...
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